Michael Charters, www.calflora.net
Plant Common Name
Catasetum Orchid, Orchid
This entry has yet to be reviewed and approved by L2G editors.
A tremendous array of flower colors and shapes occur in the Catasetum orchid genus. It contains roughly 100 species that are deciduous in the tropical winter dry season. Dozens more hybrids, called "grexes" have been created by plant breeders. These tropical herbaceous perennials hail from hot, sultry tropical Central America to northern South America.
"Catasetum" is a Greek compound word meaning "down bristle." This group of orchids is quite unique in having different gender flowers on the same plant. Moreover, male flowers have an antenna-like trigger device that snaps pollen onto the backs of visiting bees. These pollen-laced insects then find a female flower and unknowingly pollinate it. Because male and female flowers look different, people may have considerable difficulty identifying plants, especially if growing conditions prevent development of both gender flowers on the plant.
Catasetum orchids are epiphytes - growing on tree trunks. They develop fat, fleshy pseudobulbs that attach to trees (especially old dead stumps) with their roots. Their light green, thin and soft leaves are broad lances. They shrivel and drop away by fall as the plant enters a natural winter dormancy period. Depending on species, the flowers arise in summer to late fall when leaves are still lush and present. A flower stalk rises from the base of pseudobulbs, and carry either all male flowers or all female flowers. A plant can produce both flower types, but always on separate flower stalks. The blooming season is only a few weeks.
Male Catasetum flowers are much longer petaled, wide-spreading and showier than their more cup-like female counterparts. If light is rather dim, a plant may only produce male flowers. Very bright light encourages both female and male flowers to be produced. Female flowers are also held upside-down, with the lip on the upper half of the blossom. Great variability of the size and position of flower tepals exist among species.
Grow Catasetum orchids outdoors mounted on a tree trunk or in containers, especially hanging baskets and wood-slat boxes. Use a very coarse bark nugget medium to ensure excellent water drainage. They need nearly full sun to bright dappled shade. Too little light prevents good flowering. Water these orchids freely when new growth and foliage is present. A markedly dry period is needed from fall to spring during the natural dormancy. Do not being spring watering until you see new growth emerging. Good air circulation with amply high humidity around plants is a sound cultural practice.
Full Sun, Partial Sun, Partial Shade
Central America, South America
Flower Petal Number